Breaker point grinder



June 13, 1933-. H. H. wALTERs 1,914,225

BREAKER POINT GR'INDER Filed July 15, 1951 Patented `lune 13, 1933 UNiTED STATES HERBERT H. WALTERS, OF SYRLAUSVE, NEW YORK :BREAKER rompi.1 GRINDER Application led'July 13,

This invention relates to a device for grinding the contact points of electric circuit breakers commonly used in the ignition systems of internal combustion engines of motor vehicles.

Itis well known that after a short period of use, these Contact points become pitted or coated with carbon or oxide to such a degree as to greatly reduce the power efficiency of the engine and that heretofore it has been customary to clean the points with a relatively thin iile made for that purpose.`

l'llhat is, at least one of the point supports is usually pivoted to a suitable support some4 distance from the point and' is spring pressed toward the other point to be opened intermittently by suitable engine driven cams, and when it is desired to clean the points, it is customary to turn thecam to a position which will enable the points to contact with each other under thefpressure of the spring at which time the movable contactsupport may be opened by hand sutliciently to allow the insertion of a file between the points which are then released to allow the spring to force the points into contact at both faces or" the lile.

Thefile is then moved back and forth 'between the points to remove the pits or other ac-cretions thereof, but owing to the` fact, that the movable point at least is free to move more or less axially, it is evident that this iiling action causes the points to be filed more or less rounding or out of parallelism, the result of which is to reduce the sparking efliciency in the ignition system and thereby to reduce the power of the engine.

The main object of the present invention is to avoid these objectionable conditions by the use of a relatively thin rotary grinding disk which may be conveniently inserted between the contact points and rotated at suitable speed to assure the grinding of both points in planes parallel with each other and at right angles to the axes thereof and thereby to maintain the full sparking eliciency in the ignition circuit. I

In other words, I have sought to provide a simple and highly efficient grinding unit specifically adapted for grinding ythe con- 1931. Serial No. 550,483.

tact points of circuit breakers and 'capable of being manufactured and sold at a low cost for use by individual car owners and also in public garages, so that the implement as awhole may be storedin compact-space as a J ypart of the tool kit of the car ready vfor use when needed.

Other objects and uses relating to the speciic parts of the implement will be brought out in the following description. i F

In 'the drawing i Figure 1 is a perspective view on a small scale of my improved grinding unit showing a portion of an engine and circuit breaker by dotted lines to illustrate the manner of using the implement. l Figure 2 is an enlarged vertical sectional view of a portion of my improved grinder in operative position for grinding the points, taken in the plane oiilinetQ-QI Y im Figure 3 is a top plate of the circuit breaker shown in FigurerQ together with the, adjacent portionof the grinder lin operative position.

Figure l is a vertical sectional view through 75 the motor case taken in the plane of line 4-4 Figure 6.

Figure 5 is an enlarged detail sectional view taken in the plane of line 5 5, Figure 6.

Figure 6 is a sectional yview through the 30 motor case taken in the plane of line 6-6, Figure 4.'

Figure 7 is a detail vertical sectional view vtaken'in the plane of line 7 7, Figure 3, showing a portion of thecircuit breaker case in ele- 85 vation partly broken away. Y

In order that the use of the invention may be clearly understood, I have sliownfby dotted lines in Figure -1- and by full lines in Figures -2--, 3-, and -7-, a portion of 90 a circuit breaker A- having the usual breaker points or contact members 0L- mounted upon suitable supports -band -b-, one of which as bis spring pressed by means of the spring -0- toward the other 95 and is adapted to be intermittently opened by means of an engine driven rotary cam *de shown more clearly in Figure -3-.

The grinding unit forming the subject matter of the present applicationcomprises 100 a motor case -1- containing a helical spring motor -2 and a relatively large gear 3- meshing with a pinion llwhich is secured to one end of the shaft This shaft -5- is journaled at one end in suitable bearings in the motor case -1- to extend axially therefrom, and is adapted to be rotated by the spring motor -2- through the medium of the gears -3- and -4L-, the other end of the shaft being provided with a collar -6- splined thereon for axial movement and adapted to receive and support a grinding disk -7- of emery, carborundum or equivalent material, the collar -6 being preferably made in sections, in screw engagement with each other for clamping the grindin g disk -7- between them.

The motor case -1- constitutes what may be termed a hollow handle by which the shaft -5- with the grinding wheel or disk -7- thereof may be manipulated for properly adjusting the grinding wheel between the breaker points -aas shown more clearly in Fig. 7. The larger gear -3- within the handle -lis secured to a suitable shaft 8* which is journaled in opposite end walls of the handle or motor case -lfor relative rotary movement therein.

The spring motor -2- is preferably of the helical type having its inner end rivet-ed or otherwise secured to the shaft -8- and its outer end attached at a clamping bolt -9 to the peripheral wall of the case -l-. As illustrated, one of the end walls -lof the motor case -lis removable and held in place by clamping bolts -9-, one of which serves as a means of attachment of the outer end of the spring mm2- to the peripheral wall of the motor case (see Fig. 6).

One end of the shaft -8- is provided with an angular socket --8- for receiving a suit able key by which the spring 2 may be wound to place it under the desired tension for operating the gears -3- and -lland shaft -5- together with the grindingv wheel A brake lever -1()- is pivoted intermediate its ends at -10- to the end walls of the motor case m1- within the periphery thereof and has one end -extended from its pivot in the direction of rotation and closely adjacent the periphery of the gear wheel -3- and is provided with a brake shoe llnormally spring pressed against the periphery of the wheel -3- by means of a spring -l2- of sufficient tension to cause the brake shoe -llto normally hold the gear n-3- against rotation through the action of the spring motor Q- The other end of the brake lever -3- is extended outwardly through an opening 13 in the peripheral wall of the motor case -1 and is provided with a handle 14C- by which it may be depressed against the action of the spring 1Q to release the gear wheel -3- and thereby allow the motor 2- to rotate the grinding disk 7 through the medium of the shaft -5- and gears -3- and -4-.

An additional brake shoe -15 is mounted upon the inner end of an adjusting screw -16- which in turn is engaged in a threaded aperture in the peripheral wall of the motor case -1- and is provided at its outer end with a handle -17- by which it may be adjusted to bring the shoe -15- into more or less close contact with the periphery of gear wheel -3- so that by properly adjusting the screw -16, friction of the brake-shoe 15- with the periphery of the wheel i5- may be set to govern the speed of rotation of the wheel and grinding disk driven thereby.

In other words, the brake shoe -15- and its adjusting screw -l6 serve as a governor for regulating the speed of movement of the grinding disk through the medium of its driving shaft -5- and gears 3n and -4- when the brake lever -9- is released from its braking position* An additional hollow handle -18- is journaled upon the outer end of the shaft -5- at opposite ends of the collar -6- to assist in properly position the grinding disk -7- between the breaker points -a-, said additional handle 18M being held against axial movement by means of a screw 19- engaging in an annular groove -20- in the adjacent portion of the shaft -5-'.

As previously stated, the collar -6- carrying the grinding disk --7-` is splined upon the shaft --5- for slight axial movement thereon and for this purpose, the opposite end bearings of the handle -18- on said shaft are arranged in slightly spaced relation to adjacent ends of the collar as shown more clearly in Fig. 7.

The object of this slight axial movement of the grinding` disk is to facilitate its entrance between the breaker points czwhen the latter are separated by hand and also to enable the grinding disk to automatically adjust itself axially to rotate in the plane at right angles to the axes of the breaker points or parallel with the meeting faces thereof so as to assure the grinding of both faces in parallel planes.

The supplemental handle -18- is provided with a sight opening 21- in its upper side and also supports a magnifying lens -22 directly under the sight opening, which together with the lens affords a convenient means for visually locating the position of the grinding wheel relatively to the breaker points awhen adjusting the de vice for use.

Operation When using this device for grinding the contact points az-the motor case or hollow handle -1- is held in one hand to support the grinding disk -7- in position for entry between the points -a while the brake lever -10- is still in its braking position to hold the grinding disk and its driving means against rotation after which the supporting members -bm for the breaker points affare separated by hand to enable the grinding disk to be inserted between the points whereupon the member -b will be released to allow the breaker points to contact with the opposite faces of the grinding disk.

The supplemental handle -18- is then grasped by the other hand of the operator and, with the finger of the hand holding the motor case -1-, the operator may depress the handle I4- of the brake lever to release the brake -l1- and thus permit the l rotation of the gear -3- by the spring motor -2-, the rotary motion of the Wheel -3 being transmitted through the gear 4 and shaft -5- to the grinding disk -7-, which in turn eects the desired grinding of the breaker points -a-, it being understood that the governing shoe -l5- will regulate the speed of rotation of the gear -3- and parts driven thereby.

It is evident, however, that in case the brake shoe -1lshould fail to hold the wheel 3 against rotation, the brake shoe 15- may be adjusted by means of its screw -l6- to effect a positive holding 0f the gear wheel and parts operated thereby.

It is also obvious that various changes may be made in the detail construction of various parts of the grinding unit without departing from the spirit of the invention.

What I claim is 1. A device for grinding the breaker points of electric ignition systems comprising a hollow handle, a spring-motor within the handle, a rotary shaft having one end journaled in the handle, a grinding wheel on the other end of the shaft, and means actuated by the spring-motor for rotating said shaft, saidv grinding wheel being splined on the shaft for relative aXial movement, and means on the shaft for limiting the axial movement of the grinding wheel in opposite directions.

2. In a device for grinding the breaker points of electric ignition systems, a shaft, means for rotating the shaft, a grinding disc splined on the shaft to rotatel therewith and for relative axial movement thereon and adapted to be inserted between the breaker points, and a handle having bearings at oppesite -ends of the grinding disc for receiving adjacent portions of the shaft and for holding the shaft with the grinding wheel thereon in position for grinding the breaker points.

In witness whereof I have hereunto set my hand this 6th day of July, 1931.

HERBERT H. WALTERS. 

